Nonsticking obturator for direct current relays

ABSTRACT

This invention relates to a nonsticking obturator for direct current relays.

United States Patent Inventor Rodney Hayden Wentworth, Ontario, CanadaAppl. No. 822,530 Filed May 7, 1969 Patented Apr. 6, 1971 AssigneeUnited-Carr Incorporated Boston, Mass.

NONSTICKING OBTURATOR FOR DIRECT CURRENT RELAYS 1 Claim, 5 Drawing Figs.

U.S. C1 335/196, 335/187 Int. Cl 110111 1/26 Field ofSearch 335/196,

185,187,133, 200; ZOO/166 (B8) [56] References Cited UNITED STATESPATENTS 1,799,651 4/1931 Siegmund 200/166(B8) 2,837,616 6/1958Jaidinger..... 335/133 3,119,911 1/1964 Cherry..... 335/185 3,158,71211/1964 Fligue 335/196 FOREIGN PATENTS 535,565 11/1955 Italy 335/2001,104,895 6/1955 France 200/166(B8) 1,553,062 12/1968 France 200/166(B8)Primary Examiner-Harold Broome Att0rneysPhilip E. Parker, GordonNeedleman, James R.

OConnor, John Todd and Hall and Houghton ABSTRACT: This inventionrelates to a nonsticking obturator for direct current relays.

Patented April 6, 1971 FIG. PRIOR ART PRIOR ART INVENTOR RODNEY HAYDENfiMAMW F lG.5

ATTORNEY NONSTICKING OBTURATOR FOR DIRECT CURRENT RELAYS SUMMARY OF THEINVENTION This invention relates to a nonsticking obturator for directcurrent relays.

It is the main object of the present invention to communicate electricalcurrent to relay contacts of an obturator-type relay to generatemagnetic fields at right angles rather than in parallel at the region ofthe contacts.

It is a further object of the invention to provide for the conduction ofelectricity in obturator-type relay components associated withthe'electrical contacts thereof whereby the electrical fields generatedin the region of the contacts are mutually exclusive. I

With the foregoing and other objects in view the invention generallyconcerns an obturator class of direct current relay having contactmembers carried by magnetic field generator current conductingmagnetizable contact portions and characterized by: structure supportingsaid portions each relative the other in crosswise positions of minimuminterference of magnetic fields generated by currents conducted thereby.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged sectionalelevation of an obturator structure of the prior art in the region ofthe relay contacts indicating the directions'of electrical current uponcontact of same;

FIG. 2 is a section on line 2-2 of FIG. 1 and illustrates the generationof magnetic fields by the currents in the prior art structure of FIG. 1,which fields tend to hold the contacts in engagement;

FIG. 3 is the plan view of a pair of contacts and contact arms in anarrangement according to the invention illustrating current directionsand generation of magnetic fields in mutually exclusive array;

FIG. 4 is an underside perspective of the contact array of FIG. 3illustrating a particular form and arrangement of relay contactsespecially adapted to accomplish the objects of the invention; and

FIG. 5 is a side elevation of a relay embodying an obturator and contactarrangement of the invention.

DESCRIPTION OF THE EMBODIMENTS In the drawings obturator contactportions 10, 11 of the prior art are shown in FIGS. 1 and 2 havingcontact members l2, l3 thereon in closed, energized and engaged positionwith electrical current flowing therethrough in opposite directions ofarrows x and y respectively. As shown in FIG. 2 the electrical currentdirections set up magnetic fields having magnetic flux directions RandT, which being opposite cause such fields to be attractive. Thus evenif portions 10, 11 are nonmagnetic, the fields generated will cause thecontact members l2, 13 to be held into firm engagement while current isbeing conducted therethrough. Where, however, the portions 10, 11 aremade of a magnetizable material as is desired in the class of obturatorwith which this invention is concerned, then such portions becomemagnetized pennanently due to the setting up and collapsing of themagnetic fields R and T progressively during the making and breaking ofcontacts l2, 13 serving an electrical circuit (not shown). Thus if suchobturator is used in a relay form as a buzzer the initial frequency ornote will gradually lower in pitch until the contacts finally appear tostick. Such condition is due to permanent magnetism in the portions 10,11 and is not due to characteristics of contact members l2, 13.

The problem of the prior art described with reference to FIGS. 1 and 2may be overcome by resorting to the invention disclosed in FIGS. 3, 4,and 5.

In FIG. 3 portions 10a, 11a are shown in plan view wherein one portionis oriented at with respect to the other. More precisely, the contactportions of the obturator are located to conduct electrical current innonaligned directions .x", y preferably at a maximum angle A of relativeorientation of The invention also contemplates a special form of contactmember as shown in FIG. 4 wherein semicylindrical or half round contactbars 12b, 13b are mounted crosswise; i.e. at 90 to one another topresent their curved 14, 15 surfaces to one another for point contact inthe line of action indicated by chain line 16. Such half round contactmembers with their curved surfaces opposing in crosswise configurationof relative orientation are simple to fabricate and mount on theportions 10b and 11b and engage by a minimum area of contact.

In the assembly shown in FIG. 5 obturator 17 of springlike magnetizablematerial is clamped by its bottom arm 18 to insulate base l9 by ironcore member 20 energizing coil 21 to provide a gap 22 with the free arm23 thereof presenting a contact portion 24 mounting contact member 25adapted to engage crosswise disposed contact member 26 on the othercontact portion 27, being a stationary flange of rigid standard 28extending upwardly from base flange 29 fixed to base 19. The stationaryflange comprising the other contact portion 27 is disposed at rightangles in its current carrying function to the direction of electricalcurrent flow in portion 24 and arm 23 of obturator 17.

It will be apparent that if obturator portions 10 and 11 of FIG. Icarried current in the same direction that the contact members would indue course be difficult to bring to closure or engagement because thefields generated would then be in opposing relationship. In theinvention the current directions in the two portions are transverse eachwith respect to the other whereby the respective magnetic fields do notinterfere either in an opposing or attracting sense.

Iclaim:

l. A direct current electrical relay comprising an obturator formed of acontinuous length of conductive material having a free arcuate portionextending through substantially of are between a free arm portionextending tangentially therefrom and forming a part thereof, and anintegral base portion, an electromagnetic coil, the coil assembled underand spaced from the free arm portion, an electrical contact on the freeend of the arm portion, and a second electrical contact including acontactportion and support means spaced from and beneath the free end ofthe arm portion, the contact portion extending transversely across thedirection of the free arm portion and the direction of the current inthe free arm portion being in transversely relationship to the directionof the current in the contact portion and each contact having anelongated semicylindrical configuration and the contacts being in thesame geometric relationship as the free end portion is to the contactportion. I

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UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,573,689 Dated April 6, 1.971

Inventor (5) Rodney Hayden It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Abstract: delete "This invention relates to a nonsti obturator fordirect current relays.": insert This is a: obturator having elongatedcontacts housing axes that are 1' right angle relation to each other.This arrangement will cause the contacts to generate magnetic fields atright ang to each other.

Column 1, line 7, insert An obturator of the class with which thisapplication is concerned is formed of a continuous strip of ferrousmaterial in such manner as to provide in the region of the contactstructure of the relax; two parallel spaced apart metal portions one ofwhich is a movable armature portion and another of which is a stationarycontact portion. The substantially parallel spa apart armature andcontact portions upon communication of electrical current through thecontacts causes electrical current to flow in opposite parallel spacedapart direction thereby generating an electrical field causing thecontacts be held in the closed position. In result, the relay mayoperate in somewhat irregular fashion. If components of th obturator inthe region near the contacts are formed of fer material an additionalcondition of permanent magnetism may arise which increases throughcontinued use of the relay. over a period of time a permanent magneticfield may be set causing the contacts to stick and ultimately to remainclos Signed and sealed this 21 th day of August 1971.

(SEAL) Attest:

EDWARD M.FL'ETCHER, JR. Attesting Officer WILLIAM E. SCHUYLER, JR.Commissioner of Patents

1. A direct current electrical relay comprising an obturator formed of a continuous length of conductive material having a free arcuate portion extending through substantially 180* of arc between a free arm portion extending tangentially therefrom and forming a part thereof, and an integral base portion, an electromagnetic coil, the coil assembled under and spaced from the free arm portion, an electrical contact on the free end of the arm portion, and a second electrical contact including a contact portion and support means spaced from and beneath the free end of the arm portion, the contact portion extending transversely across the direction of the free arm portion and the direction of the current in the free arm portion being in transversely relationship to the direction of the current in the contact portion and each contact having an elongated semicylindrical configuration and the contacts being in the same geometric relationship as the free end portion is to the contact portion. 